1. Field of the Invention
The present invention relates to an ink-jet-type image forming apparatus which records an image by discharging ink droplets onto a recording medium.
2. Description of the Related Art
Typical ink-jet recorders of this type are serial-type ink-jet recorders and line-type ink-jet recorders. In serial-type ink-jet recorders, a recording head is mounted on a carriage reciprocated in a direction perpendicular to the conveying direction of a recording medium, and an image is formed on the recording medium by alternately repeating conveyance of the recording material with a predetermined pitch and reciprocating movement of the carriage. In line-type ink-jet recorders, a recording head whose length is substantially equal to the width of a recording material is used, and an image is formed on the recording material together with conveyance of the recording material.
However, in the above-described conventional techniques, when discharging ink droplets from the recording head, ink mist comprising very small ink droplets which do not contribute to image recording is generated in addition to ink droplets which contribute to image recording. This ink mist flies around the recording head, and adheres to and is accumulated on components present within the range of the flying the ink mist, thereby causing problems. For example, if a platen facing the recording head via a recording medium is stained with the ink mist, ink stain adheres to the back of the recording material. Furthermore, if the viscosity of ink on the platen increases, sliding between the recording medium and the platen is degraded, thereby causing a failure in conveyance of the recording medium, such as a sheet jam, skew, a crease, undulation or the like. In the case of serial-type ink-jet recorders, there is the possibility that ink mist adheres to a guide member of the carriage, thereby causing a failure in operation due to an increase of resistance against scanning. When performing control of the position of the carriage using a signal from an optical encoder disposed in a main scanning direction, accuracy in detection is degraded by adherence of ink mist to the encoder, thereby causing degradation in accuracy of recording, a failure in position control, or the like.
The present invention has been made in consideration of the above-described problems.
It is an object of the present invention to provide an image forming apparatus which can always perform a stable image recording operation by collecting ink mist while preventing an increase in the size of the apparatus and complexity of the apparatus, and degradation in the reliability of the apparatus.
It is another object of the present invention to provide an image forming apparatus which includes a member capable of maintaining a constant ink-mist collecting capability in an ink-mist discharging path.
According to one aspect of the present invention, an image forming apparatus for forming an image in a predetermined image forming region by discharging ink droplets includes an image forming unit for forming an image in the predetermined image forming region, and a suction unit for sucking air including ink mist generated when forming the image by the image forming unit. The suction unit includes at least one suction port provided near the image forming region, and an exhaust path formed below the suction port. The exhaust path includes a slope inclined in a direction crossing a direction of flow of the air including the ink mist sucked into the exhaust path, and an ink collecting portion provided on the slope.